Ask them to check for any incoming e-mail scanner running on their local
machine. If so, ask them disable the same. Also check the .qmail file in the
user's folder for any duplicate entries.
2009/9/11 Bulend Kolay <bma...@ihlas.net.tr>
> I use vpopmail on qmail.
> I have many customer domains on that mail server.
> One of these customer domains tells me that, they rarely receive the same
> mail a few times. That problem becomes nearly once a week for this
> I haven't any complain from my other customers.
> They use outlook or o.express for their mails.
> What may the problem be ?
> Do I have to change my configuration ?